SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '809dc2bb18e78181bc842a2df32a162c61840c6db4162d2f89e0cea4bc268f30' 
  AND token = '2jI3rpTtnjwoFDEYM/jG/OHwhStN3UKjvNihR3/65yQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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