SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf070f59337628304f8a878ea8e484b944ed92ba20b01e17d348ddcfa24a5437' 
  AND token = '6wq7zgAcedZ1csVUG+wYiCKpkS9jtBMBzQKVzWPPimE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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