SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7494d3dffad96fc4081c93e415c0b10d024080bfe363032b6ca23ac87a74f92c' 
  AND token = 'suwbjM3swgUd5VtyOrL8Udzo0VE9DE1akdZ91VBNGyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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