SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '5669b223e6e9794ec615b1590d288cd12a73163de5442aa15729fce77a3befd2' 
  AND token = 'YtWKeGGUVnJJuuMEwA1SuP15UjRRXI0hDEDJPFX417o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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