SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3faf8580f1343a7d3042ac3ddb85883546f42b982b90c26fc1e45cf7369f369f' 
  AND token = '7Pr7J5mKDHNqfA3nd/vHhLVIjyaUUTBMY8SlqXcKJaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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