SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfc0c3c9e4f4fd1275e53942102d0a26b56efad4f14d576ac54a92367b3e20d8' 
  AND token = 'AaLMTtD2XXXGXTBCKLXOml2lAhSP5A6yCqzZJiE19Jc=' 
  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"
    }
  }
}