SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d4a46d6dafde97bbd80b05794565563154feb8a444f7c55a7f405ec239043bb' 
  AND token = 'kUZxnyjtET4Nz4EliuUZgkf1gwdhG5xj4eBOmLsN7Ys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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