SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c2b7b0c58cbc898283471be04862dce39420d73035c0d4b99e4682a7d64d2d73' 
  AND token = 'FtPqoPMx9VGnOhQoHbE3FT8cmVH6FukZxzddT+X0ldI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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