SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d9e38f40b3a075617bf2c782b305b6525f1495842ff38bf094abffeb8b26416' 
  AND token = 'j3qLbdPqcV3jFeGW+fjVxrOm8f5xkF3dulWI0QyeXK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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