SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '70f602e05e35de90f1cd33dd1295eb55261b7423fd77c650299a9ddab3cbe901' 
  AND token = 'Z7BPLdwZr/lfTQB/2ODG8puaA3b8SgYSi9YERWFkqRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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