SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac64b384ae1ff18e6f81eaeaa5c40f3658e980bc3c8ec9225fea442649d5a2ba' 
  AND token = 'UUqP3UZRzYGzYjCIVAV5NTSLNwZH3cUuiPqjWZkLKcY=' 
  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"
    }
  }
}