SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e854d45cd7a9a2100eea63f678dd945de7a1ef169aa87ce5e9e396557b3c6d3' 
  AND token = 'DtrdoRW4UmDh02KiEACgP43fQq8d2jZMXpMDhFjias0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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