SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24ce6cdc919b0a559646e64bdab472202a57c946e564ae035aaf4ff5db96799a' 
  AND token = 'v/QSLWlhXxR5lrl5jhFfH2E0omWonLJFwHM9nFne4bE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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