SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6d8f16b546a98b2b6d28838151046eba45511e57c4a2cbe5cd00f58c919cf5f' 
  AND token = 'tC4J2owxOgmuozG3B3WETr73WKMOjeErz573Y9zCL1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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