SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94ccce829fd1f283cff98cc51744ccfe51db553bbaa8efd760876fbf4d7a1784' 
  AND token = '8LYbVI+4YeSlvoB2gMK9nwd/P7CELSA2Zj/YYl3qy1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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