SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c32c26d45935934035209df4479eae41114f9497bdc89bdcbf7e1f73cfe8cafa' 
  AND token = 'WfhXoh+VX5Ug1kA0RN5iohwnbzpq1S0V2ueKdIPTWA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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