SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '830a927403cc39edc384f069a01603ca147063ab404cd790503d3e24737d59d5' 
  AND token = 'hzC4ntblYBkERdk4V0SGgBWc02BL/3kAO1o1fphgVvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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