SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f47c9e219e247d8bdc85aad469e4173e3cf546167fcbbee4970e91d77aae2f97' 
  AND token = 'rFYF4dAiPh/4k9SJrSBGBywwOROAXYoxLxBJHr8zzkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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