SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac3df695caed602def27c64ded23ecfeda1d830d81c18d8d1cc6dc1eaa0d0f79' 
  AND token = '8lSYMh/q9v8NvLEyNFywF8ovboQhMFnkmlMnbdZyFY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}