SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2d5c9129c56ef93203072720204ec1ddbd9f5f4860894287daf028273aea106' 
  AND token = '/8LpFDI1qTdnW4DfTWWzU/RZM5Nx8SnUEvNA7LosrI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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