SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '636f0581118c912289bcdedf61b972cc236380e23c10d87679b3823ef67af9ed' 
  AND token = 'LsChdJ7H2TI7U+1gZYgumpx00hMkGLybK6D7gL/yAXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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