SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c07d56f8895a0eab19c38d32d052402e3b66d57f5df91f9d9ab2c3ffa94bf95d' 
  AND token = 'ZjTpfFlvW8/lDfRvLo4pyCD6tcKQkWvUTtqcpLhPWCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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