SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f349983cd74984385473fdda689dfda322ad269dbd1f81189c6b345b6b63e30c' 
  AND token = '1Iyhx1Lg+fu/8MIPurVrBH/dbuxpcqAkOFNJ3K6mWEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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