SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65591a47df4cc29d3100037edca867fe9e3b7ef05d95d9cf53c052db72ebd932' 
  AND token = 'q77/jKftFNqpz+xaB/ecIFZFbE72MCcmXVmmbXHZqjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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