SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '337dfe6e56605bdc3c37653891e59aac957f250615f0e54e0f03aaba333904b7' 
  AND token = 'L0CbJtlu7WOmwnryEFRt4iQ67uF4wK3eYTo6m7FRt6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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