SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30b2b2b1e655d9fbf61d2c17f3db4c6499adf61ca09521c7290d6bbbacabbef8' 
  AND token = 'JORixlEfS4tzS5aYTE8kftUiqmXfJ5CO08qABD6FYDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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