SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c475725fc7751deebbd1cc8c75d5fd9950cd32af7a624361ad540083a19086f' 
  AND token = 'ielVnTBCQ1Xkp13SYW6HI9FPSjX/pkXqCXDPUuHWPto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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