SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc277005d00a3336280a7a3a10e23b0837fa31a5598c5061307a975e66b59dcb' 
  AND token = 'KjlQBBJ3oDpG+//6qn32bpBppg2DV8B6bZB/rPQ0bBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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