SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ebf760686a225bac845127bd7a39bb4b73b971a7c1d9b61d3a2bd46c61ab6d6' 
  AND token = '7iZGeiUGQgHSG277Z8lPMd0vSv6P0np7WWN6Xv1diRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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