SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86288e255d4674c470f34736f6046981dda0a2a115c843e665b7bfa79006e197' 
  AND token = '1iEp3hCJBLjGX8dg+pLMso4Zdmjgvb7x3HFHHxGzFek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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