SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ad8d6085aa35b56997072e754872dfb4f5dcbd0a342fb297247cf59d20a7961' 
  AND token = 'VXsdboZmy/MfgWyh3lII0ZTL+yLpBaOztq/9WHgA9vQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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