SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80cb1ba3cf1e8cdb1fdb19fc8b2cb40ea9e8739182dba99ab96312bce2b178a6' 
  AND token = 'K5pKRe/reXXlKGKMcwUW2KZbO2cD9s94SmYQArpcL1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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