SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '327483b47663052dd38a411d92e0963078c02dd8d90bc89271cc89a43adf2ffe' 
  AND token = 'jaT8gUvuR+I/fwfbCJGZ7VzfFXF5yyewOXklze8K6Go=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00092

JSON explain

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