SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4b95d5d17c2e8626559329a7528cf0f830d7db21b54453b9f6794ad71ff7a62' 
  AND token = 'y0GU6zH7mqzBm2n/hjmcU5H57bPwk2t/Z9oJXNL1C3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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