SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7adf2a8d30aaaf67c29325562387ccf05137d7a2743782898591d6e8fca3bf41' 
  AND token = 'Exn6fPILnszi8/Q209/0X2AD+SnjXVkQyG+YAE61q6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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