SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d19f4f097514b579f19116dfa0833783796128389095caef97bd7c1855980e8' 
  AND token = 'VLKs+iJuCXyOT0W/EZ0LtkQOacfit2mczZjcfJkvhyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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