SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd57325319574ef11f20ec81c65a4fc469db3e4a840b557ff1b6d6de362da79c' 
  AND token = 'E3lwVq3zQc6qRA5xzJBILnCSX6DoOvK/Sj3GS6TTUVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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