SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05bb847395bb8a10a694ffea4f8ef2959721e886ace2564cd8453aba390caa1a' 
  AND token = 'Slu0hwaMECKKJdqndHvDYaUYDtZJBVqV5wNI+fDDE4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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