SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88a2ce4577243d5e4a0a14842ef6ac333a45095299ee0c682155143bc03733e8' 
  AND token = 'cD2HCZ9zATVovwRI+IwGFCiLyaVN/fLbYolJpL7Rl4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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