SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e8134c6f99f0b9c590c8e3c2ba4551f88b40fb62f79c69bf877a8880f893ab1' 
  AND token = '/WCi2zBAIygCOHO+K2ReA6qBVLUppPlfZl2WJU/ELEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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