SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2cae3c9f534e4bca3c4e693b6345b8fcba3cf0576c4c97f9239a2f883060ecd' 
  AND token = '64BNgamIYnfxls+8gyhimuFm9NxFsFyw089Z7KpTNq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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