SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7bd3389273b07eae324e912c498c3cf5671b5c55b50901ef69a62f89f214d2d8' 
  AND token = 'yspnrjL/hIumGYTIULxpCIKD+k9GePr9J9JeW6TzO2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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