SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1d766096e91399cd0e8644a0eec72687c81f3198e1a94853e067475a4ff95f2' 
  AND token = 'V8Uz6uAPTR0CBQnM9Q6s+U9kLZwddLLt0z6ZlPZuJz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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