SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92cc85a0b771c76b1b234f7f6906d5fcd5965cb49eaede15e13c6f05eda09e54' 
  AND token = 'HHx2TLoLWDxlXzsd6pu/GkcxNZUyCdTqA8xykxCv0iU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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