SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc5363c39b75a1ba06b442f59ea3ff23b74ebb7497b1e9107bd6a9d47edf56b1' 
  AND token = 'c1Bq+lmpy9XaSvyqZs4nm/VrKVBpC9Z/TKZnDZdBjfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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