SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34f1b9dfdfeaabcea6283f73b14a01aa919da18c62fc43aec2da1383e062ebab' 
  AND token = '5MGbSmbcN4KVLLWkqnuIws93dp8ZFWRAkEnzAF38WB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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