SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d1402f9683b11a42814c0692bfd5561899874456ff3a6d48f2735a556fde8b0' 
  AND token = 'bgRDwOYwTX94/pJQye+258q/3haLxXCpX5R3Bqgd/eA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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