SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75b153d333005a408302e62dd7c9bd756a8059a61df028920c66770e57bc11e8' 
  AND token = 'jKkP6AL0GXGQ/fQJlbV6P+5CBTg3Kz3GkYDcARHiUXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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