SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '765b0e159d1044ea922540be59bfd6e55a97b057168034042cf58d1e03a7841c' 
  AND token = 'HBkEotBSwKbRy3/ZsHFj0hOvPjdrPf20uwUa9Wl5ipw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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