SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82f1f823687b093d946175be5e72bb6c25ebeb114060819402bdc617f0d7a3fd' 
  AND token = 'yrgKLEZt7R3qJuFlBoYOhn+AglBuf8gJi80yLDs4hrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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