SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5f45480449808cc05d77f8739fd04617b15e82b77e75872bc6572a8c0c5c6ac' 
  AND token = 'uA08mp0QIOdGyht3iaiVVUYBsSNJQBxy4vSKVPOud14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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