SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e48bf308216f0b48449c2a37930f1d41ec17466213d400e3e2ce107fd83dc6d7' 
  AND token = 'kgAGNrzg9xyaVGGarm8FPfhTK2YCbZNUeuBhMyetMkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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