SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5296f98456e3cfcd226903ba4e95c0962d8cbedff04e709199333e4d63b91550' 
  AND token = 'qyifWAE2btalMggaoVLUPUTCZBEy1vE/mOwLvbkRJEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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