SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fa39ecefb99c1b639b65dfe3e05a4334cf7528fa3989ab7cb29944d288940c6' 
  AND token = 'jnp7KTmWYJwRsHT4poiLn77AKBJQP/XJ6bvp0TIAybo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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