SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cc9913a9fa9f8c0335c2382e379f18300e8ccc0ccdb3215e4c474bb238c2b9c' 
  AND token = 'uHPckcZzcz79T1BoVMbKQIofwTlG2emzxLaSlfMDuWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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