SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1776baf38b5a3f5465f804915d3d2bc3f7357580c6d08d217b3182efc3f7d62' 
  AND token = 'hhogdf+9Tq2zizEtJTITrxSzLwU/IvXArVWL+t+0wFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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