SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1a3975a4cb449fd82f49277dd070845cd80339c5dea468806c437d60c490dae' 
  AND token = 'qpeXNxs1XNA5VV6kSv+RugBLoWgDXvs2mygos7sfvcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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