SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be9e562f4c75e04b655f8dcd008c507662ed81ba3ee0ef0a9e1b83f85dd46910' 
  AND token = 'hQPB7RwQ76XyFw/uSnhBeEVq1wUzzLOJyJUVC2/ZhNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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