SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23569b62eaf7a75c7361148dd822b2a92aca80cc1c237908b46bc25fd7198dee' 
  AND token = 'DUHxG2TlKwr2+jJxQALk4v9kMY0+sbyKVoh9CEqUmuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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