SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60d4fe4aa3f7908ac35eccc21195d37633bb8effc9544ce36e303b6fbbf8bb78' 
  AND token = 'mOrKokO6jMycDIjU7j3K6sTSK/bKCfaLjJfNRjzqv84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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