SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f063653425a75ab1df84a1f8072220c7d208a74f56d926a7ac8724290d36f63' 
  AND token = 'slRIXdwdMK34DLZBJSEN8YOynkSMMf7bIKmfPGgAglE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}