SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22b298874a97e1f0a6c9d6440d413088d65e6543dabfa7e6f2dc6c4f5680ae9f' 
  AND token = 'FZVV1xrelY0PGUz/ZHWVPWLT9WHkGJxbIq21YuNoCdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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