SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95b2ebbd9faa48fe6fc2febff781e9d8eb2f6bfbf7966f89098391b47f6c17bc' 
  AND token = 'RK1C3ZA2mSyAyZeMLLttpkMeB1njCTAXYRcFkf0Kc4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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