SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e73dd3dea59d9764b99088855c816753a88bd251cffd2ebbb8f5724749248cdd' 
  AND token = 'XRp+0pekXMCK+H1U/1I77vAxulh8kfL2hJpYCluf+xA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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