SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '23186dc1225656d82fe64bab29eb49e0149566fffd8cdafb187a579cf06b7022' 
  AND token = 'goQOnnLIHJzUujVT1gIOiRjKML/6Cjq6g94wibKlLx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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