SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c5e64993c46846c05edff4512fe7923fee66a53a03ddd1f7b1824af68f14449' 
  AND token = 'mHebXN93ys+Hl3wCGH0BXs4Ej3gJEfDreZgmiI9bRoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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