SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a08d63dacccf87ca747f7935ebc97931e886818765245b07a886eaabf3308b8a' 
  AND token = 'gSjBGbnwgRzN+b92huPPQ3UotMR+IaA1srSCAB5IDws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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