SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c7c5746fa9003b2fb502ddad9aacbc31b3e8948723e63142cb27a6366515995' 
  AND token = 'NnyFjRpB05uv2cCIoF1hTXKCOMsqTcMCUZqP1+W6b+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}