SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ec8799f0d46962da499ffa12def5da7d2bcec341093edbd37dd3b6ebaec8178' 
  AND token = 'dgTNHXMjuSSLrBRfY8RBViqG/5Lgs8JtbuVt4e0s51k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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