SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd166569ec72bdfe6bcf107518055fb40b48fe80a7c6899cd6a584db37143417b' 
  AND token = 'kKz3hI/R4AsXYs1npkx9S9pGBVhZ5FI4y4aZyM1xEiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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