SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f22ff66b1ab9adb20223d6128cde2211f5c28834f6746e8b58b619070916f43c' 
  AND token = 'pSqaRSQpheRztE3QrAqD0Emk0c6yw7hR9eIzHuFKnZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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